Wind driven apparatus for an aerial power generation system include driven elements and controls. The driven elements are configured and shaped to provide maximum force from both lift and drag during the downwind phase of operation and minimum force during the upwind phase. The driven elements have a sail portion with a leading edge and a trailing edge. The controls change the driven elements between high force configurations for downwind operation and low force configurations for upwind operation, adjust the pitch and azimuth angles of the driven elements, and control the camber.